Riverine Flood Risk in Arizona
All Arizona counties ranked by FEMA National Risk Index riverine flood score
Riverine Flood risk — rivers and streams overflowing their banks after heavy rain or snowmelt — is rated for 15 of 15 Arizona counties in FEMA's National Risk Index. Maricopa County carries the state's highest riverine flood score at 99.9, with $1.12B in expected annual riverine flood losses.
7 Arizona counties are rated High or Very High for riverine flood, and expected annual losses from riverine flood total roughly $1.98B statewide. The full ranking below links to each county's complete 18-hazard risk profile.
County Rankings — Riverine Flood
| # | County | Riverine Flood Score | Rating | Ann. Freq. | Ann. Loss |
|---|---|---|---|---|---|
| 1 | Maricopa County | Very High | 8.46 / yr | $1.12B | |
| 2 | Pima County | Very High | 12.82 / yr | $347M | |
| 3 | Mohave County | High | 10.43 / yr | $74M | |
| 4 | Coconino County | High | 8.04 / yr | $86M | |
| 5 | Pinal County | High | 3.89 / yr | $92M | |
| 6 | Yavapai County | High | 7.25 / yr | $70M | |
| 7 | Cochise County | High | 6.21 / yr | $44M | |
| 8 | Gila County | Medium | 5.46 / yr | $35M | |
| 9 | La Paz County | Medium | 2.93 / yr | $24M | |
| 10 | Yuma County | Medium | 1.32 / yr | $32M | |
| 11 | Navajo County | Medium | 4.14 / yr | $20M | |
| 12 | Santa Cruz County | Medium | 2.75 / yr | $18M | |
| 13 | Apache County | Medium | 2.75 / yr | $11M | |
| 14 | Graham County | Low | 1.71 / yr | $9M | |
| 15 | Greenlee County | Very Low | 0.93 / yr | $3M |
15 Arizona counties with measurable riverine flood risk. See the national riverine flood ranking or all Arizona counties by overall risk.
Frequently Asked Questions
Which Arizona county has the highest riverine flood risk?
Maricopa County has the highest FEMA riverine flood risk score in Arizona at 99.9 (Very High), with $1.12B in expected annual losses and about 8.46 events per year.
How many Arizona counties face significant riverine flood risk?
15 Arizona counties record measurable riverine flood risk in FEMA's National Risk Index; 7 of them are rated High or Very High.